Abstract: A crank and connecting rod mechanism, comprising at least one piston, which reciprocates within at least one cylinder, comprising: at least one connecting rod, comprising: a piston end pivotally connected to the at least one piston, a crank end; at least one gear set, comprising: a crankpin, the crank end pivotally connected to the crankpin; a crank gear; a crank gear shaft, the crank gear rotatably mounted on the crank gear shaft, the crankpin located between centerline of the crank gear shaft and radius of the pitch circle of the crank gear; a stationary gear, the crank gear meshing with the stationary gear, the crank end driving the crankpin, which drives the crank gear and the crank gear shaft about the stationary gear; the crank pin and the crank end rotating about the stationary gear and following the path of a roulette of a centered trochoid about the stationary gear.

Abstract: The horizontally opposed center fired engine improves on the traditional design of the horizontally opposed engines and center fired engines with a better engine geometry. The present invention utilizes four pairs of opposing pistons to compress a larger volume of air-fuel mixture within four different cylinders. The four different cylinders are radially positioned around a center axle in order to achieve a perfectly symmetric engine geometry. The center axle consists of two different shafts spinning in two different directions, which could drastically reduce engine vibrations in the present invention. Engine vibrations are caused by a change in engine speed and result in a loss of energy. Due to the design, the present invention will only experience energy loss in the form of entropy and friction. Thus, the present invention can convert a higher percentage of chemical energy into mechanical energy than any other internal combustion engine.